There is well known a control apparatus for a hybrid vehicle provided with an engine and a motor/generator functioning as a drive power source, an automatic transmission which constitutes a part of a power transmitting path between the drive power source and drive wheels and in which a shifting action is performed by selective engagement of a plurality of coupling devices, and an electric storage device giving/receiving electric power to/from the motor/generator. For example, this corresponds to a hybrid vehicle described in JP-2014-223888A. It is disclosed in JP-2014-223888A that an input torque to the automatic transmission is controlled by motor/generators (the first motor/generator and the second motor/generator in JP-2014-223888A) during a shifting action of the automatic transmission on the basis of an output torque of the engine and a transmitted torque of the coupling devices, such that an angular acceleration value defined as a value representing a rotating state of an input rotary member of the automatic transmission (angular acceleration value of the second motor/generator in JP-2014-223888A) coincides with a target value.
During a power-on shift-down action of the automatic transmission, a transmitted torque of the coupling devices may become insufficient for some reason, and the value representing the rotating state of the input rotary member of the automatic transmission may become larger than the target value (i.e., a rotating speed of the input rotary member of the automatic transmission may rise faster than the target). In such a case, the input torque to the automatic transmission is reduced lower than an original input torque to the automatic transmission when the value representing the rotating state of the input rotary member of the automatic transmission is made equal to the target value (e.g., an output torque of the motor/generator used as the basis of the input torque to the automatic transmission is reduced), so that the value representing the rotating state of the input rotary member of the automatic transmission coincides with the target value. In this case, the power corresponding to a reduction amount of the output torque of the motor/generator is stored as electric power into the electric storage device. If a chargeable electric power of the electric storage device is insufficient for the power corresponding to this reduction amount, the output torque of the motor/generator cannot sufficiently be reduced such that the value representing the rotating state of the input rotary member of the automatic transmission coincides with the target value. When the chargeable electric power of the electric storage device is insufficient, a rotating speed of the engine can be raised to consume as an inertia power a surplus power corresponding to a torque that cannot be reduced by reducing the output torque of the motor/generator with respect to an amount of the input torque to the automatic transmission required to be reduced for providing control such that the value representing the rotating state of the input rotary member of the automatic transmission coincides with the target value, and the input torque to the automatic transmission can thereby be reduced as much as necessary, so as to provide control such that the value representing the rotating state of the input rotary member of the automatic transmission coincides with the target value. However, the overspeeding of the engine may occur, possibly resulting in deterioration in component durability or giving a strange feeling to a driver.